Hectograph blanket having a copy mass containing a small percentage of glycol type or sorbitol type solvent



Sept. 16, 1941. w J CHAMPION 2,255,912

HEGTOGRAPH BLANKET HAVING A COPY MASS CONTAINING A SMALL PERCENTAGE OF GLYCOL TYPE OR SORBITOL TYPE SOLVENT Filed June 26, 1940 IN VENTOR. [WI/2'02?! (ital/ 02022, BY L of Robert C. Bour, Serial No. 313,191.

Patented Sept. 16, 194i UNITED STATES PATENT OFFICE I HECTOGR-APH BLANKET HAVING A COPY MASS CONTAINING A SMALL PERCENTAGE OF GLYCOL OR SOBBITOL TYPE SOLVENT William 1. Champion, Bcrwyn, Ill.,assignor to Ditto, Incorporated, Chicago, 111., a corporation of West Virginia Application June 26, 1940, Serial No. 342,447

Claims.

The invention relates to hectograph blankets.

An object of the invention is to provide a hectograph blanket having a copy-mass which gives exceptional copy strength and good runnitnig qualities.

I have discovered that the inclusion of a very small amount of a glycol type solvent or sorbitol in an ordinary glue or gelatin hectograph mass greatly enhances the brightness of the initial copies without any deleterious effect on the toughness or on the running characteristics.

Quantities of from one-half to five percent, and

cent, which might be expected. to give enhanced copy strength, are unsuitable for many hectograph blankets because they cause partial dissolution and softening of the cellulose ester lacquer commonly used in backings for hectograph blankets.

Suitable glycol type solvents include ethylene glycol, diethylene glycol, diethylene glycol-monoethyl ether, and diethyleneglycol monobutyl ether. Sorbitol is also suitable. The preferred material is ethylene glycol. I

Hectograph masses containing the above materials in proportions of from one-half to five percent, and preferably one-half to two, percent, require much less conditioning than other hectograph masses of similar copy strength. However, the masses containing such substances do not bond as well to linseed oil and other drying oils as is ordinarily desirable. I have discovered, however, that a very satisfactory bond can be obtained and therefore a highly satisfactory hectograph blanket when the hectograph mass containing the glycol type solvent or sorbitol is applied to a backing covered with a layer containing a wetting agent as is disclosed in the application Suitable wetting agents are the sulfonated naphthenes, preferably when used in admixture with cellulose esters. Other suitable wetting agents are lauryl sulfate, sulfonated castor oil, sulfated fatty acid amides, secondary alcohol sulfates, and alkyl aryl sulfonates. In general suitable wetting agents hydrophobic in character, with the addition of one or more groups of a strongly hydrophilic nature which act as solubilizing groups for the compound. v

The invention is further illustrated in conjunction witlrthe accompanying drawing, in which Fig. l is a sectional view of a hectograph blanket illustrating one embodiment of my invention.

Referring to Fig. 1, the reference character I is a gelatinous copy mass containing about one percent ethylene glycol. This copy mass I is secured by means of a film or layer 2, comprising a wetting agent, to a flexible backing consistin of paper, cloth, or other fabric base 4 coated on both sides with a relatively non-adhesive cellulose ester lacquer 3 and 5. In the preferred embodiment of the invention, the bonding layer 2 comprises one of the usual cellulose derivative lacquers containing a wetting agent having a hydrophobic long .chain aliphatic radical attached to a hydrophilic-803R radical in which R il's a hydrogen or metal.

o more clearly set forth the practice in accordance with the invention and to more specifically point out the nature of the produce and process contemplated thereby, a specific illustrated example is hereinafter set forth, it being understood that this example'illustrates one embodiment which as given satisfactory results and is not int ded to restrict the invention thereto.

Example 30 parts by weight of gelatin or 225 bloom is soaked in parts by weight of water for 1 hr.;

7 parts by weight of ethylene glycol is mixed with 300 parts by weight of glycerin, the mixture are composed of a hydrocarbon chain which 'is' heated to C. and then added to the swelled gelatin with agitation. The colloidal solution so formed'is then applied to -a backing which is coated with a cellulose ester lacquer containing a sulfonated naphthene.

While there have been shown and described certain-embodiments of the invention, it is to be understood that it is capable of many modifications. Changes, therefore, may be'made without departing from the spirit and scope of the invention as described in the appended .claims, in

which it is the intention to claim all novelty inherent in the invention as broadly as possible, in view of the prior art. g

I claim:

'1. ,A hectograph blanket comprising a backing,

a copy mass secured to one side of the backing and cellulose ester lacquer on the other side ofiglycerin, water, and from one-half to five percent of a substance selected from the group consisting of glycols, glycol ethers, and sorbitol.

2. A hectograph blanket comprising a backing,

a copy mass secured to one side of the backing and cellulose ester lacquer on the other side oi! said backing, said copy mass comprising gelatin, glycerin, water, and from one-half to five percent of a glycol. j

, 3. A hectograph blanket'comprislng'a backing, :a copy mass secured to one side of the backing and cellulose ester lacquer on the other side of said backing, said copy mass comprising gelatin,

I 4; A hectograph blanket comprising a backing,

a copy mass secured to one side of the backing and cellulose ester lacquer on the other side of glycerin, water, and from one-half to five per- 15 cent of a glycol ether.

said backin .said copy mass comprising gelatin, glycerin, water, and from one-half to five percent of sorbitol. 5. A hectograph blanket comprising a backing, a copy mass secured to one side of the backingand, cellulose ester lacquer on the other side of said backing, said copy mass comprising gelatin, glycerin, water, and from one-half to five percen of ethylene glycol.

WILLIAM J.'CHAMPION. 

